The City of Mobile is implementing a comprehensive GPS/GIS initiative to map its entire stormwater system, providing a survey-grade inventory of all structures and their associated pipes. As Mobile experiences increasingly intense rainfall events and localized flooding, understanding the capacity and condition of the stormwater system has become essential. A complete and accurate stormwater system map allows the City to identify deficiencies, predict storm water behavior, and prioritize maintenance and improvements. It also enhances the City’s ability to plan and respond effectively during storm events.

Phase I of the project, completed in 2024, documented all stormwater structures within the 2021 City limits. Survey teams collected survey-grade data on inlets, manholes, cleanouts, outfalls, and connecting pipes, documenting each feature’s depth, size, material, and physical condition. All surveyed features underwent a rigorous QA/QC process before being imported into a GIS database, where their spatial relationships and flow connectivity to pipes, ditches, and channels were added.

Phase II expands the effort to include three areas annexed by the City in 2023, ensuring the stormwater inventory reflects Mobile’s current geographic footprint. Once fully completed, this mapping effort will provide Mobile with a strong foundation for decision-making, improved flood mitigation, and more efficient stormwater system management across the entire city.

This presentation will detail the data collection process, collaborations, challenges encountered, lessons learned, and the innovative solutions applied to ensure accuracy and efficiency. It will also preview forthcoming applications of the completed stormwater map, illustrating how this dataset will support planning, project design, emergency response, and long-term stormwater infrastructure management.